Extracting Mutual Interaction Rules Using Fuzzy Structured Agent-based Model of Tumor-Immune System Interactions.

BACKGROUND: There are many studies to investigate the effects of each interacting component of tumor-immune system interactions. In all these studies, the distinct effect of each component was investigated. As the interaction of tumor-immune system has feedback and is complex, the alternation of each component may affect other components indirectly. OBJECTIVE: Because of the complexities of tumor-immune system interactions, it is important to determine the mutual behavior of such components. We need a careful observation to extract these mutual interactions. Achieving these observations using experiments is costly and time-consuming. MATERIAL AND METHODS: In this experimental and based on mathematical modeling study, to achieve these observations, we presented a fuzzy structured agent-based model of tumor-immune system interactions. In this study, we consider the confronting of the effector cells of the adaptive immune system in the presence of the cytokines of interleukin-2 (IL-2) and transforming growth factor-beta (TGF-ß) as a fuzzy structured model. Using the experimental data of murine models of B16F10 cell line of melanoma cancer cells, we optimized the parameters of the model. RESULTS: Using the output of this model, we determined the rules which could occur. As we optimized the parameters of the model using escape state of the tumor and then the rules which we obtained, are the rules of tumor escape. CONCLUSION: The results showed that using fuzzy structured agent-based model, we are able to show different output of the tumor-immune system interactions, which are caused by the stochastic behavior of each cell. But different output of the model just follow the predetermined behavior, and using this behavior, we can achieve the rules of interactions.

New insights into the expression profile of MicroRNA-34c and P53 in infertile men spermatozoa and testicular tissue.

Spermatogenesis is proliferation and differentiation processes of stem spermatogonia into mature spermatozoa controlled by the genes responsible for transcription and post transcription levels. MicroRNAs (miRNA) are  the key factors during gene expression in RNA silencing and post-transcriptional regulation. They play main roles in regulation of early and late spermatogenesis, and reproduction. In this study, we investigate the role of miRNAs in infertile males.The patients were assigned to five groups based on semen analysis (n=55), including normozoospermic (N), moderate oligoasthenoteratozoospermic (MOAT), severe oligoasthenoteratozoospermic (SOAT), obstructive azoospermia (OA) and non-obstructive azoospermia (NOA). Quantitative RT-PCR was recruited to study the expression of miR-34c and tumor suppressor p53 gene. In addition, malondialdehyde (MDA) and DNA fragmentation was measured. Network analysis was performed using Pathway Studio web tool (Elsevier). Our results revealed statistically significant increased expression of miR-34c in moderate oligoasthenoteratozoospermic, non-obstructive azoospermia and an increased expression of p53 in MOAT, SOAT and NOA males. Also, the percentage of DNA fragmentation and oxidative stress was significantly higher in infertile groups (MOAT and SOAT) than other groups. These findings provide a novel molecular mechanism of gene regulation during cell-cycle and apoptosis in sperm, which gives a new regulatory insight into male infertility in terms of molecular diagnosis.

Effects of a new advanced glycation inhibitor, LR-90, on mitigating arterial stiffening and improving arterial elasticity and compliance in a diabetic rat model: aortic impedance analysis.

BACKGROUND AND PURPOSE: We determined the effects of treatment with LR-90, an inhibitor of advanced glycation end products, on the mechanical properties of the arterial system in streptozotocin (STZ)-induced diabetic Sprague Dawley rats, using aortic impedance analysis, and further investigated the effects of LR-90 on the progression of aortic pathology. EXPERIMENTAL APPROACH: STZ-induced diabetic rats were treated with or without LR-90 (50 mg L(-1) in drinking water) for 8 weeks and compared with control groups. Arterial BP measurements, various metabolic parameters, aortic histopathology, collagen cross-linking, AGE accumulation, and RAGE protein expression in aortic tissue were determined. Pulsatile parameters were evaluated using a standard Fourier series expansion technique and impulse response function of the filtered aortic input impedance spectra. KEY RESULTS: LR-90 reduced glycated haemoglobin and triglycerides levels, although it had no effect on the glycaemic status. LR-90 did not affect arterial BP, but prevented the diabetes-induced increase in peripheral resistance and variations in aortic distensibility, as it reduced aortic characteristic impedance by 21%. LR-90 also prevented the elevation in wave reflection factor, as indicated by a 22.5% reduction and an associated increase of 23.5% in wave transit time, suggesting it prevents the augmentation of the systolic load of the left ventricle. Moreover, LR-90 inhibited collagen cross-linking and the accumulation of AGE and RAGE in the vasculature of diabetic rats. CONCLUSIONS AND IMPLICATIONS: Treatment with LR-90 may impart significant protection against diabetes-induced aortic stiffening and cardiac hypertrophy and provides an additional therapeutic option for treatment of AGE associated diabetic complications.

LR-90 prevents dyslipidaemia and diabetic nephropathy in the Zucker diabetic fatty rat.

AIMS/HYPOTHESIS: Previous studies have shown that LR-90, a new inhibitor of AGE formation, prevented the development of experimental type 1 diabetic nephropathy. In this study, we examined the effects of LR-90 in the Zucker diabetic fatty (ZDF) rat, a model of type 2 diabetes and metabolic syndrome, and investigated the mechanisms by which it may protect against renal injury. METHODS: Male ZDF rats were treated without or with LR-90 from age 13 to 40 weeks. Metabolic and kidney functions and renal histology were evaluated. AGE accumulation and the production of the receptor for AGE (AGER) were measured. Profibrotic growth factors, extracellular matrix proteins and intracellular signalling pathways associated with glomerular and tubular damage were also analysed. RESULTS: LR-90 dramatically reduced plasma lipids in ZDF rats, with only modest effects on hyperglycaemia. Renal AGE, AGER and lipid peroxidation were all attenuated by LR-90. LR-90 significantly retarded the increase in albuminuria and proteinuria. This was associated with reduction in glomerulosclerosis and tubulointerstitial fibrosis, concomitant with marked inhibition of renal overproduction of TGF-beta1, connective tissue growth factor, fibronectin and collagen IV. Additionally, LR-90 downregulated the activation of key mitogen-activated protein kinases (MAPKs) and nuclear factor kappa B (NF-kappaB) in the renal cortex. CONCLUSIONS/INTERPRETATION: These results support our earlier studies on the renoprotective effects of LR-90 on type 1 diabetic nephropathy and provide further evidence that LR-90, an AGE inhibitor with pleiotrophic effects, may also be beneficial for the prevention of type 2 diabetic nephropathy, where multiple risk factors, such as hyperglycaemia, dyslipidaemia, obesity, insulin resistance and hypertension, contribute to renal injury.

A new advanced glycation inhibitor, LR-90, prevents experimental diabetic retinopathy in rats.

BACKGROUND: Diabetic retinopathy is associated with accumulation of advanced glycation end products in the retinal microvasculature. LR-90 is an effective multistage inhibitor of advanced glycation with renoprotective and anti-inflammatory properties. AIM: To explore the role of LR-90 in the progression of experimental diabetic retinopathy. METHODS: Streptozotocin-induced diabetic Sprague-Dawley rats were treated with LR-90 (50 mg/l in drinking water) for up to 32 weeks. At the end of the study, eyes were enucleated and subjected to trypsin digestion and staining with light green/haematoxylin. Acellular capillaries and pericytes were quantified in random fields using light microscopy. RESULTS: In the LR-90-treated diabetic animals, acellular capillary numbers were reduced to 1.63 (0.20) from 2.58 (0.49) (p<0.05) in diabetic controls. LR-90 treatment also restored the pericyte deficit from 18.12 (0.98) in diabetic rats to 24.19 (0.76) (p<0.001). CONCLUSION: These findings show that LR-90 can effectively inhibit important lesions of diabetic retinopathy. This agent has potential for preventing retinopathy in patients with diabetes.

LR-90 a new advanced glycation endproduct inhibitor prevents progression of diabetic nephropathy in streptozotocin-diabetic rats.

AIMS/HYPOTHESIS: Advanced glycation and lipoxidation endproducts have been implicated in the pathogenesis of diabetic complications, including diabetic nephropathy. LR-90, a new advanced glycation endproduct inhibitor, was investigated for its effects on the development of renal disease in diabetic rats. METHODS: Diabetic animals were randomly allocated into groups receiving LR-90 or vehicle (untreated). Age- and weight-matched non-diabetic rats were studied concurrently. Body weight, plasma glucose, glycated haemoglobin, urinary albumin and creatine excretions were measured serially. Kidney histopathology, AGE accumulation in cells and tissues, protein oxidation, were also examined. In vitro assays were used to assess the possible mechanism of action of LR-90. RESULTS: LR-90 inhibited the increase in albumin and creatinine concentrations, and concentrations of circulating AGE in diabetic rats without any effect on glycaemic control. LR-90 treated-rats also showed higher body weights than untreated diabetic rats. LR-90 prevented glomerulosclerosis, tubular degeneration and collagen deposition in the kidney. AGE-induced cross-linking and fluorescence of tail collagen were reduced by LR-90 treatment. LR-90 also decreased AGE accumulation in kidney glomeruli and nitrotyrosine deposition in the renal cortex. In vitro, LR-90 was capable of reacting with reactive carbonyl compounds and was a more potent metal chelator than pyridoxamine and aminoguanidine. CONCLUSION/INTERPRETATION: LR-90 reduces in vivo AGE accumulation, AGE-protein cross-linking and protein oxidation, and could be beneficial in preventing the progression of diabetic nephropathy. The AGE inhibitory and therapeutic effects of LR-90 could be attributed, at least in part, to its ability to react with reactive carbonyl species and/or potent metal chelating activity that inhibits glycoxidative-AGE formation.

Routine laser assisted hatching results in significantly increased clincal pregnancies.

PURPOSE: To elucidate the appropriateness of current indications for assisted hatching (AH) in cleavage stage human embryos and to confirm our preliminary findings that only young patients (about 67%) benefit from AH. METHODS: Prior to transfer, 2 of 3 embryos selected for ET were subjected to laser assisted hatching (LAH). Control group consisted of patients matched by similar characteristics and protocol except LAH was not performed. RESULTS: The clinical pregnancy rate in women < or = 36 years was 64.9% (24/37) for embryos subjected to LAH but was significantly lower (p = 0.029) in the control (33.3%; 10/30). The implantation rate in women < or = 36 years in the test group was 38.1% (40/105) that was significantly higher than that of the control group (17.5%, 14/80; p = 0.0039). CONCLUSIONS: LAH is beneficial for women < or = 36 years but not for women > or = 37 years, for embryos with thin zonae (< or = 16 micron) but not with thick zonae (> or = 17 micron), and for those with repeated failures (37-50%).

PACAP mediates the neural proliferative pathway of Mastomys enterochromaffin-like cell transformation.

BACKGROUND AND AIM: Pituitary adenylate-cyclase activating peptide (PACAP) is a more potent proliferative agent than gastrin for rat enterochromaffin-like (ECL) cell proliferation in vitro. The role of this neurotransmitter during gastrin-mediated ECL cell tumor formation and gastrin-autonomous ECL cell neoplasia is unknown. METHODS AND RESULTS: ECL cell transformation was induced in the Mastomys using 16 wk H2 receptor blockade of acid inhibition. Examination of the epithelial fundic mucosa demonstrated that PACAP-immunoreactivity significantly increased in the tumor mucosa compared to the naïve stomach, and was associated with ECL cells. Naïve and tumor ECL cells were then purified (approximately 95%) from Mastomys and the presence of all three PACAP/VPAC receptor subtypes was demonstrated by polymerase chain-reaction amplification. Thereafter, cells were maintained in short-term (48 h) primary cultures. PACAP significantly (p<0.05) increased 24 h bromo-deoxyuridine uptake (approximately 4-fold) in both cell types with estimated EC(50) values of approximately 4x10(-16) M and approximately 2x10(-16) M, respectively. Specific receptor antagonists (PAC1/VPAC1) of PACAP competitively inhibited these proliferative effects in naïve cells. Oligonucleotide antisense directed against PAC1 significantly inhibited PACAP-stimulated DNA synthesis by approximately 85% (p<0.05) in tumor cells. CONCLUSION: PACAP is a potent and effective modulator of ECL cell proliferation. The expression of this neuropeptide and its receptors, particularly PAC1, suggest the existence of a neural regulatory pathway of ECL cell proliferation and transformation.

Evidence that pioglitazone, metformin and pentoxifylline are inhibitors of glycation.

Enhanced formation and accumulation of advanced glycation end products (AGEs) have been proposed to play a major role in the pathogenesis of diabetic complications, and atherosclerosis, leading to the development of a range of diabetic complications including nephropathy, retinopathy and neuropathy. Several potential drug candidates as AGE inhibitors have been reported recently. Aminoguanidine is the first drug extensively studied. However, there are no currently available medications known to block AGE formation. We have previously reported a number of novel and structurally diverse compounds as potent inhibitors of glycation and AGE formation. We have now studied several of the existing drugs, which are in therapeutic practice for lowering blood sugar or the treatment of peripheral vascular disease in diabetic patients, for possible inhibitory effects on glycation. We show that that three compounds; pioglitazone, metformin and pentoxifylline are also inhibitors of glycation.

Novel inhibitors of advanced glycation endproducts (part II).

Enhanced formation and accumulation of advanced glycation endproducts (AGEs), have been implicated as a major pathogenesis process leading to diabetic complications, normal aging, atherosclerosis, and Alzheimer's Disease. Several potential drug candidates as AGE inhibitors have been reported recently. The aim of this study was to develop classes of novel inhibitors of glycation, AGE formation, and AGE-crosslinking and to investigate their effects through in vitro chemical and immunochemical assays. A total of 92 compounds were designed and synthesized. The first 63 compounds were reported before. Nearly half of the 29 novel inhibitors reported here are benzoic acid derivatives and related molecules, and found to be potent inhibitors of multistage glycation, AGE formation, and AGE-protein crosslinking. All 29 compounds show some degrees of inhibitory activities as detected by the four assay methods, 9 compounds demonstrated high percent inhibition (PI) in all tests, 30 to 40 times stronger than aminoguanidine.

A new rapid method to detect inhibition of Amadori product generated by delta-gluconolactone.

Advanced glycation endproducts (AGEs) have been implicated as a major pathogenic process in leading to diabetic complications. An increasing number of drug candidates have recently been developed as potential inhibitors of AGEs. Aminoguanidine, a hydrazine-like molecule is the first drug that was extensively studied both in vitro and in vivo as an inhibitor of AGE formation. Several assay methods have been proposed to determine the inhibitory effect of glycation inhibitors, including assays based on inhibition of specific fluorescence generated in the course of glycation and AGE-formation; assays based on the inhibition of AGE-protein crosslinks, and dimer and trimer formation; and specific ELISA assays using anti-AGE antibodies for quantitative measurement of AGEs in the presence and absence of the inhibitor. However, none of these assays can accurately evaluate chemical intermediates and products generated during the early stages of glycation. We have devised a new rapid assay method for evaluation of the early stage of glycation (Amadori product). This assay is based on the interaction of delta-gluconolactone (delta-Glu), an oxidized (ketoaldehyde) analogue of glucose, with hemoglobin present in blood samples. The assay involves determination of the percentage of glycated hemoglobin (HbA1C) after incubation at 37 degrees for 16 h with delta-Glu (50 mmol/L) using a dedicated ion-exchange high-performance liquid chromatography (HPLC) system. The results using normal human red blood cells show HbA1C levels to be 180% higher than baseline controls. The effects of various inhibitors are determined by measuring the levels of HbA1C by the compound in question compared to delta-Glu-treated vehicle only blood samples. This new assay provides a relevant and physiological model to study glycation and potential inhibitors. Furthermore, it offers a means to differentiate between inhibitors of the early and late stages of glycation and provides a rapid method of screening large numbers of potential inhibitors of glycation. Contrary to the assay methods, which are based on the measurement of fluorescence of fluorophores generated during glycation, the proposed assay does not suffer from the possible problem of overlapping and interference of AGE-specific fluorescence with the intrinsic fluorescence of the inhibitor compound.

Novel inhibitors of advanced glycation endproducts.

Enhanced formation and accumulation of advanced glycation endproducts (AGE's) have been proposed to play a major role in the pathogenesis of diabetic complications, aging, atherosclerosis, and Alzheimer disease leading to progressive and irreversible intermolecular protein crosslinkings. This process is accelerated in diabetes and has been postulated to contribute to the development of a range of diabetic complications including nephropathy, retinopathy and neuropathy. Several potential drug candidates as AGE inhibitors have been reported recently. Aminoguanidine is the first drug extensively studied both in vitro and in vivo. We have developed a new class of compounds as potent inhibitors of glycation and AGE formation. The novel inhibitors reported here are aryl (and heterocyclic) ureido, and aryl (and heterocyclic) carboxamido phenoxy isobutyric acids and related molecules, which were found by in vitro assay methods to be potent inhibitors of multiple stage of glycation and AGE formation.

Hb Watts [alpha 74(EF3) or alpha 75(EF4)Asp-->0]: a shortened alpha chain variant due to the deletion of three nucleotides in exon 2 of the alpha 2-globin gene.

We have identified a new, slightly unstable alpha chain hemoglobin variant, present in a Mexican-American family. Amino acid sequencing and mass spectral analysis of the aberrant peptide (alpha T-9) of the variant revealed that the aspartic acid is deleted either at position 74 or 75 of one of the alpha-globin chains. Sequencing of the amplified alpha 2- or alpha 1-globin genes revealed a trinucleotide deletion (GAC) at codon 74 or 74 of the alpha 2 gene. Although the aspartic acid residues of 74 and 75 of the alpha chain are neither a heme nor an inter chain contact, the slight instability of Hb Watts may be due to disturbance of the central cavity of hemoglobin by the deletion of an aspartic acid residue in the EF helix. Hb Watts is the first example of a trinucleotide deletion in the alpha 2-globin gene.

A novel intrachromosomal rearrangement in the beta-globin gene found in an African-American family.

We describe here a deletion of 34 nucleotides from the 3' end of the first intervening sequence of the beta-globin gene covering the AGGC splice junction, and the insertion of 32 nucleotides of the delta-globin gene at the same location. This gene rearrangement was detected in three members of an African-American family. The proband, a 28-year-old female, and her mother had a history of chronic anemia. One of her two brothers, who inherited the same gene defect, was apparently healthy with no symptoms of hemolytic anemia. The proband, her father, and her two brothers, including the one who carried the beta-globin gene rearrangement, were found to be heterozygous for alpha-thalassemia-2 (-alpha 3.7). Although the AGGC splice junction is disrupted (AGGC-->AGAT), the invariant AG has remained intact after this gene rearrangement. Our investigations could not detect any defect in RNA processing in the affected beta-globin genes. The discrepancies between the phenotypes and the globin chain synthesis ratios of the mother, her daughter, and her son who inherited the same gene defect at their beta-globin genes, remain unexplained.